Expansion link bracelet



Se t. 7, 1965 A. PENTTINEN 3,204,399

EXPANSION LINK BRACELET Filed Oct. 10, 1962 II, 21 M FIGZ m w i I I {I l United States Patent C) 3,204,399 EXPANSION LINK BRACELET Emil Arvid Penttinen, Teollisuustie 12, Kerava, Finland Filed Oct. 10, 1962, Ser. No. 229,578 Claims priority, applicatitsm Finland, Apr. 10, 1962, 74 62 9 Claims. (Cl. 59-79) The invention relates to an expansion bracelet, e.g., a wrist watch bracelet of suitable metal or the like. There are many types of expansion bracelets but all are too Complicated in structure and for this reason have high cost of manufacture, particularly if the bracelet is made so elastic and extensible that the same may be slipped over the hand of the wearer and fit the wrist.

The object of this invention is to provide a full expansion bracelet simple in structure. A feature of the invention resides in the provision of a series of box-like link members each including a smaller box-like section having as an extension thereof a larger box-like section with an end wall, said larger box-like section being provided with a slot in the said end wall to receive the smaller box-like section of the next adjacent link member which extends into the larger box-like section of the first-mentioned link member and that within the smaller box-like sections of the link members are disposed spring members having elements adapted to protrude through apertures in the two oppositely disposed side walls of the said box-like sections and to move within said apertures when tension is applied to expand the bracelet and when the said tension is relieved, said protruding elements together with the slot bearing end wall of the larger box-like section of the next adjacent link member about the smaller box-like section serving to prevent the series of link members from becoming disengaged and that the said spring members are shaped to always urge the smaller box-like sections of the link members inwardly as much as possible and into the larger box-like sections of the link members.

In the drawings- FIG. 1 is a longitudinal sectional view of one portion of the bracelet in fully extended condition.

FIG. 2 is a longitudinal sectional view of one portion of the unextended bracelet.

FIG. 3 is a sectional top plan view of a portion of the bracelet in extended and unextended condition.

FIG. 4 is an axonometric view of the bracelet in unextended condition and partly in section.

FIG. 5 is an axonometric view of the spring member used in the bracelet shown in FIG. 3.

FIG. 6 is a top plan view of an alternative form of spring member.

FIG. 7 is a side view of the alternative form of spring member.

The bracelet is composed of box-like link members which a spring prevents from becoming disconnected. Each link member consists of a smaller box-like element or portion formed to have a smaller box-like section 1 and as an extension thereof a larger box-like section or portion 2 so that at the junction point of said sections is formed an annular shoulder or flange 3. The smaller boxlike section 1 has two of its oppositely disposed narrow side walls taken away so the same are provided with an aperture 4 substantially the width and length of the side wall and bounded by top and bottom walls and the end walls. In the end wall of the larger box-like section 2 is a slot or opening 6 limited by pairs of inwardly projecting wall portions 5. The slot 6 receives the smaller boxlike section 1 of the next adjacent link member, as shown in FIGS. 1-4. The smaller box-like section 1 of the link member and the larger box-like section 2 of the link member are of the same length with the result that when 3,204,399 Patented Sept. 7, 1965 the end wall of the smaller box-like section meets the inside face of the side wall of the larger box-like section of the like member the end wall of the larger box-like section of a second link in the series of link members will bear against the shoulder 3 formed by the side wall of the larger box-like section of the first-mentioned link member, as clearly shown in FIG. 2.

As has already been mentioned hereinabove the link members are connected together by spring members. FIGS. 3 and 5 show one form of spring members that can be used in the bracelet of the invention. This spring consists of a resilient strip 7 the ends of which are bent to form legs 8 the extensions of which form an angle. The strip 7 is provided with eyes 9 at the ends where the legs and said strip meet. This spring is of length such that when the spring is disposed transversely within the smaller box-like section 1 of the link member the eyes 9 will protrude from the lateral openings 4 in the opposite side walls of the smaller box-like section and will extend at least approximately to the side walls of the larger box-like section of the next adjacent link member which encircles the smaller box-like section 1, as clearly shown in FIG. 3. The legs 8 flatten against the inner face of the end Wall of the smaller box-like section and always tend to force the spring against the larger box-like section 2 of the link member. Since the springs in the smaller box-like sections of the link members protrude from the smaller box-like sections the springs will prevent the link members in series from becoming disconnected because the eye portions 9 of the spring elements which are rigid in the collapsed position bear against the inner faces of the inwardly projecting side walls 5 of the larger boxlike sections in the next adjacent link member encircling the smaller box-like section.

The operation of the bracelet is as follows: When the bracelet is in unexpanded condition the smaller box-like sections 1 of the link members are drawn in as far as possible by spring action, of. FIGS. 2 and 3. When the bracelet is being expanded the smaller box-like sections of the link members will be withdrawn from the larger box-like sections 2 of the link members. At the same time the springs will be stressed more and more because the springs cannot move away since the spring ends protruding from the smaller box-like sections bear against the inner face of the side walls 5 of the larger box-like sections and consequently the springs will slide in the openings provided in the side walls of the smaller sections and become stressed and finally non-resilient and rigid as shown in the lower part of FIG. 3 which, together with FIG. 1 is illustrative in showing the construction when the bracelet is in fully expanded condition.

FIGS. 6 and 7 show an alternative form of spring that can be used in the bracelet of the invention. This spring is formed by a spiral spring band 10 shaped like a truncated pyramid. The base portion of this spring is so large that the ends in the lower layer 11 thereof will protrude from the oppositely disposed openings 4 in the smaller box-like section wherefore this spring operates in manner similar to that of the first described spring. When the spring is stressed its spiral windings will telescope and the spring will become a rigid flat spiral. From this it follows that this spring will not take up much space in compressed condition and therefore permits greatest possible expansion of the bracelet while locking the links to each other.

The invention is not limited to the embodiments herein described for the same can be modified in many different ways within the scope of the invention for the characterizing feature is that the bracelet link member has two successive sections, a smaller section and as its extension a larger section whereinto the smaller section of the next adjacent link member extends and that the link members tion of said row, said smaller portions being narrower ina direction transverse to said row than said larger portions and having lateral openings, and said larger portions having transverse projections extending inwardly toward said smaller portions; and a plurality of springs, each spring being located in one of said smaller portions and having an inner part abutting the same, and outer parts projecting through said lateral openings into the correlated larger portion and abutting said projections so that said springs normally hold adjacent links in a closely spaced position, said springs being compressed when said smaller portions are moved out of said larger portions and having a final non-resilient condition blocking movement of saidsmaller portion in said larger portion-by rigidly connectingsaid smaller portion relative to said projections. I

2. An expansible link strap comprising a row of hollow links, each link having a larger portion, and a smaller portion located in the larger portion of an adjacent link and being movable, in the same in the longitudinal direction of said row, said larger and smaller portions forming a shoulder between each other, said smaller portions being narrower in a direction transverse to said row than said larger portions and having lateral openings, and said larger portions having transverse projections extending inwardly toward said smaller portions; and a plurality of springs, each spring being located in one of,

said smaller portions and having an inner part abutting the same, and outer parts projecting through said lateral openings into the correlated larger portion and abutting said projections so that said springs normally hold adjacent links in a closely spacedposition in which one end of said larger portion of each link abuts said shoulder of the adjacent link so that said smaller portion of the respective adjacent link iscompletely located in said larger portion with the end of said smaller portion 4. An expansible link strap comprising a row of hollow links, each link having a larger box-like portion-open at one, end of the link, and a smaller box-like portion located in the larger'portion of an adjacent link and being movable in the same in the longitudinal direction of said row, said larger and smaller portions forming a shoulder between each 'oth'er, said smaller portions being narrower ina direction transverse to said row than said larger portions, being closed at the other end of the link and having lateral openings, said smaller portions having top and bottom walls sliding on inner surfaces of said larger portions, and said larger portions having at said one open end of said link a pair of transverse? projections extending inwardly toward lateralzopenings of said smaller portions; andaplurality of springs, each spring beinglo cated in one of said smaller portions and having an inner part abutting the same, and outer parts projecting through said lateral openings into the correlated larger portion and abutting said pair of projections so that said springs normally hold adjacent links ina closely spaced position in which said open end of said larger portion of each link abutssaid shoulder of the adjacent link so that said smaller portion of the respective adjacent link is completely locatedin said larger portion with the end of said smaller portion located in close proximity of the other end of said larger portion, the length of said smaller portions being not greater than the length of said larger portions, said springs being compressed when said smaller portions are moved out of said larger portions-and ha vcated in close proximity of the other end of said larger portion, the length of said smaller portions being not greater than the length of said larger portions, said springs being compressed when said smaller portions are moved out of said larger portions and having a final non-resilient condition blocking movement of said smaller por-' tion in said larger portion by rigidly connecting said smaller portion relative to said projections.

3; An expansible link strap comprising a row of hollow links, each link having a larger box-like portion open at one end of the link, and a smaller box-like portion located in the larger portion of an adjacent link and being movable in the same in the longitudinal direction of said row, said smaller portions being narrower in a direction transverse to said row than said larger portions, being closed at the other end of the link and having lateral openings, said smaller portions having top'and bottom walls sliding on inner surfaces of said larger portions, and said larger portions having at said one open end of said link a pair of transverse projections extending inwardly toward lateralopenings of said smaller portions; and a plurality of springs, each spring being located in one of said smaller portions and having an inner part abutting the same, and outer parts projecting through said lateral openings into the correlated larger portion and abutting said pair of projections so that said springs normally holdadjacent links in a' closely spaced position,

said springs being compressed when said smaller portions ing a final non-resilient condition blocking movement of said smaller portion in said larger portion by rigidly connecting said smaller portion relative to said pair of projections.

, 5. An expansible ,link strap as set forth in claim 4 wherein each of said smaller portions has an end Wall between said top and bottom walls at said closed end, said lateral openings being bounded by the edges of said Walls.

a 6. An expansible link strap comprising a row of hollow links, each l'ink'having a larger portion, and a smaller portion located in the larger portion of an adjacent link and being movable in the same in the longitudinal direction of said row, said smaller portions being narrower in a direction transverse to said row than said larger portions and having lateral openings, and larger portions having transverse projections extending inwardly toward said smaller portions; and a plurality ofv springs, each spring being located in one of said smaller portions and having a straight portion and pair of legs extending inward from the ends of said straight portion, said legs abutting said smaller portion, and said ends of said straight portion projecting throughsaid lateral openings into the correlated largerporti-on and abutting said projections so that said springsnormally hold adjacent links in a closely spaced position, said springs being compressed by bending of said legs toward said-straight portion when said smallerportions are moved out of'said'larger portions and having a final non-resilient condition in which said Y legs abut saidstraight portion for blocking movement of said smaller portion in said larger portion by rigidly connecting said smaller portion relativeto said projection.

7. An expansible link strap comprising a row of hollow links, 'eachflink having a larger box-like portionopen at one end of the link, and. a smaller box-like portion 10- portion in said larger portionby rigidly connecting said i smaller portion relative to said pair of projections.

cated in the larger portion of an adjacent link and being movable in the same in the longitudinal direction of said row, saidsmaller portions being narrower in a direction transverse to said row than said larger: portions, being closed at the other end of the link and having lateral openings, said smaller portions having top and bottom walls sliding on inner surfaces of said larger portions, and said larger portions having at said one open end of said link a pair of transverse projections extending inwardly toward lateral openings. of said smaller portions; and a plurality of springs, each spring being located in one of said smaller portions and having a straight portion and pair of legs extending inward from the ends of said straight portion, said legs abutting said smaller portion, and said ends of said straight portion projecting through said lateral openings into the correlated larger portion and abutting said pair of projections so that springs normally hold adjacent links in a closely spaced position, said springs being compressed by bending of said legs toward said straight portion when said smaller portions are moved out of said larger portions and having a final non-resilient condition in which said legs abut said straight portion for blocking movement of said smaller portion in said larger portion by rigidly connecting said smaller portion relative to said pair of projections.

8. An expansible link strap comprising a row of hollow links, each link having a larger portion, and a smaller portion located in the larger portion of an adjacent link and being movable in the same in the longitudinal direction of said row, said smaller portions being narrower in a direction transverse to said row than said larger portions and having lateral openings, and said larger portions having transverse projections extending inwardly toward said smaller portions; and a plurality of springs, each spring being located in one of said smaller portions, each spring being a band in the shape of a spiral of frustoconical shape having a base wider in the transverse direction than said smaller portion, the central part of said spring abutting said smaller portion, and the outer parts of said band in the region of said base projecting through said lateral openings into the correlated larger portion and abutting said projections so that said springs normally hold adjacent links in a closely spaced position, said springs being compressed by moving said central part toward said base when said smaller portions are moved out of said larger portions and having a final non-resilient condition in which all windings of said spring are located in the region of said base so that said band blocks the movement of said smaller portion in said larger portion by rigidly connecting said smaller portion relative to said projections.

9. An expansible link strap comprising a row of hollow links, each link having a larger box-like portion open at one end of the link, and a smaller box-like portion located in the larger portion of an adjacent link and being movable in the same in the longitudinal direction of said row, said smaller portions being narrower in a direction transverse to said row than said larger portions, being closed at the other end of the link and having lateral openings, said smaller portions having top and bottom walls sliding on inner surfaces of said larger portions, and said larger portions having at said one open end of said link a pair of transverse projections extending inwardly toward lateral openings of said smaller portions; and a plurality of springs, each spring being located in one of said smaller portions, each spring being a band in the shape of a spiral of frusto-conical shape having a base wider in the transverse direction than said smaller portion, the central part of said spring abutting said smaller portion and the outer parts of said band in the region of said base projecting through said lateral openings into the correlated larger portion and abutting said pair of projections so that said springs normally hold adjacent links in a closely spaced position, said springs being compressed by moving said central part toward said base when said smaller portions are moved out of said larger portions and having a final non-resilient condition in which all windings of said spring are located in the region of said base so that said band blocks the movement of said smaller portion in said larger portion by rigidly connecting said smaller portion relative to said pair of projections.

References Cited by the Examiner UNITED STATES PATENTS 2,866,312 12/58 Kussmaul 59--79 2,943,437 7/60 Ihringer 59-79 FOREIGN PATENTS 1,009,411 5/57 Germany.

WILLIAM J. STEPHENSON, Primary Examiner.

CHARLES W. LANHAM, Examiner. 

1. AN EXPANSIBLE LINK STRAP COMPRISING A ROW OF HOLLOW LINKS, EACH LINK HAVINGA LARGER PORTIOIN, AND A SMALLER PORTION LOCATED IN THE LARGER PORTION OF AN ADJACENT LINK AND BEING MOVABLE IN THE SAME IN THE LONGITUDINAL DIRECTION OF SAID ROW, SAID SMALLER PORTIONS BEING NARROWER IN A DIRECTION TRANSVERSE TO SAID ROW THAN SAID LARGER PORTIONS AND HAVING LATERAL OPENINGS, AND SAID LARGER PORTIONS HAVING TRANSVERSE PROJECTIONS EXTENDING INWARDLY TOWARD SAID SMALLER PORTIONS; AND A PLURALITY OF SPRINGS, EACH SPRING BEING LOCATED IN ONE OF SAID SMALLER PORTIONS AND HAVING AN INNER PART ABUTTING THE SAME, AND OUTER PARTS PROJECTING THROUGH SAID LATERAL OPENINGS INTO THE CORRELATED LARGER PORTION AND ABUTTING SAID PROJECTIONS SO THAT SAID SPRINGS NORMALLY HOLD ADJACENT LINKS IN A CLOSELY SPACED POSITION, SAID SPRINGS BEING COMPRESSED WHEN SAID SMALLER PORTIONS ARE MOVED OUT OF SAID LARGER PORTIONS AND HAVING A FINAL NON-RESILIENT CONDITION BLOCKING MOVEMENT OF SAID SMALLER PORTION IN SAID LARGER PORTION BY RIGIDLY CONNECTING SAID SMALLER PORTION RELATIVE TO SAID PROJECTIONS. 